Polyethylene is a favored material used in constructing containers. It is cheaply produced as molded or extruded. However, polyethylene has serious drawbacks. When certain fluids such as hydrocarbon based materials are packaged in polyethylene containers, they have a tendency to seep through the container wall. This is due to the permeable nature of polyethylene.
It is an object of the invention to provide a thermoplastic additive which when blended with a thermoplastic serves as a barrier to the permeation of fluids, and in particular, hydrocarbon based materials.
It is a further object of the invention to provide a drum, bottle, container or the like capable of resisting permeation of fluids, and particularly, hydrocarbon based materials.
It is a further object of the invention to provide a thermoplastic additive which can be formed into a liner for containers of other materials, such as metal and paper products, which provides resistance to fluid permeation.
The present invention is a thermoplastic additive which is added to thermoplastics, particularly, polyethylene. The additive is comprised of a carrier thermoplastic, polyvinylidine fluoride, and aluminum stearate as a tie agent, binding the polyvinylidine fluoride and the carrier thermoplastic.
It is also possible to form the blend into a liner suitable for lining metal drums and containers of other materials, thereby serving as extra measure of protection against permeation.
Aluminum stearate is used as an agent capable of gelling or thickening aliphatic and aromatic hydrocarbons. In the present invention, its presence as an additive to thermoplastics or to thermoplastic liners reduces permeation through the container walls. If aliphatic or aromatic hydrocarbons penetrate the interior container wall or interior liner, the presence of aluminum stearate would cause a localized thickening, thereby preventing permeation.